It’s widely accepted that plants can filter pollution from the atmosphere, reducing harmful chemicals such as benzene. Since NASA’s tests on air-filtering houseplants in the 1980s, scientists have been comparing the influence of individual plants on air quality. Two common houseplants that score highly are mother-in-law’s tongue ( Sansevieria) and the peace lily ( Spathiphyllum). More recently, as part of the fight against pollution in Milan, two specially designed tower blocks (called Bosco Verticale – or Vertical Forest) were covered with over 900 trees to absorb dust, smog and heat. Hairy, rough or needle-like leaves are best for capturing pollutant particles, which are deposited on leaf surfaces or removed from the air as plants take in gases. While botanists still have more research to do in this field, it’s clear that gardeners can make a vital contribution to air quality in our homes and cities, and to the health of their inhabitants.
Emma Crawforth, Gardening Editor